Insert parts are used in large scope in sheet metal machining so as to incorporate forming threads in sheet metal plates. Receptacles are initially introduced into a sheet metal plate, and insert parts are inserted into the receptacles manually or by machine at a later time. Once the insert parts have been inserted, the insert parts may be welded to the sheet metal plate or riveted directly to the sheet metal plate upon insertion. Errors may occur when the insert parts are later inserted in the receptacles.